This invention relates to a group of novel aromatic polyethers having 9,9-biphenylfluorene group in their repeating units. The novel aromatic polyethers are useful as heat resistant synthetic resins having good solubilities in various organic solvents.
Some aromatic polyethers are known as highly heat-resistant plastic materials. Particularly aromatic polyethers shown in JP-A No. 54-90296, which have repeating units derived from diphenyl ketone or diphenyl sulfone, are excellent in mechanical characteristics such as tensile strength, elastic modulus and impact resistance, thermal properties represented by heat distortion temperature and thermal decomposition temperature and electrical properties represented by dielectric strength. However, industrial use of such aromatic polyethers as synthetic resins is quite limited since the polyethers are hardly soluble in organic solvents.
Even though a polymer possesses attractive properties the polymer is of little value as an industrial plastic material unless it has good moldability and/or good solubilities in solvents low in price and convenient for industrial handling. With respect to aromatic polyethers which have excellent heat resistance and lack melt-moldability, it is keenly desired to afford good solubilities in commonplace solvents to the polymers since practical applications of the polymers will expand if solutions are readily available for spinning into fibers, casting into films and for other purposes such as coating, painting and cementing.